Newsletter

Posted March 30, 2012 12:02 am

Copper River Highway bridge closure to last several years

The Department of Transportation & Public Facilities reminds residents and visitors in the Cordova area that the Copper River Highway remains closed indefinitely at mile 36 due to safety concerns at Bridge No. 339.

This closure will remain in effect until the bridge is replaced, which is estimated to be several years away.

The 50-mile Copper River Highway begins in Cordova and ends at the “Million Dollar Bridge.” The road, frequented by hunters and recreationists, leads to campgrounds, a lodge and vast areas of proposed resource development.

DOT&PF closed Bridge No. 339 in August of 2011. The bridge is one of 11 bridges crossing the Copper River Delta. Naturally occurring changes to the water flow between channels across the delta led to a dramatic increase in the amount of water running under the bridge. Due to the increased amount of water, 50 ft of “scour”, or erosion, was observed at the bridge in 2011. The scour lowered the channel bottom and compromised the bridge structure, necessitating the closure.

Adverse effects due to the increased flow of water from the Copper River under Bridge No. 339 was first noted in 2009. In 2010, DOT&PF and the U.S. Geological Survey began a comprehensive monitoring program at the bridge that included frequent on-site inspections and the use of bridge sensors that enabled remote observation.

Bridge No. 339 was constructed in 1977. Based on the channel configurations at that time, bridge designers estimated that water under the bridge would flow at 18,500 cubic feet per second. During the summer of 2011, USGS hydrologists measured water flows exceeding 85,000 cfs.

DOT&PF received funding in the fall of 2011 to begin the design phase of a replacement bridge; the design phase will progress through 2013, with agency permitting in 2014. Pending the availability of construction funds, the construction project could begin as early as 2015.

Private businesses hope to provide access past Bridge No. 339. For more information about access beyond the bridge, contact the Cordova Chamber of Commerce at 424-7260.